you can totally post your job ads on facebook. I know that some only use it for playing facebook games and all that but it's never general. Some also take advantage of the social network to build their own websites and facebook is one useful way to do that.

I would not click on a job advertised on facebook but then I try not to click on internet adverts so maybe it's worth a try.

I can see the value of twitter (used properly) for recruiting but facebook just feels too, well, social. I use it to keep in contact with people I would otherwise have lost contact with. On a personal level I think it's great. I did block it at work though, as jasper said, people just sit there on facebook ALL DAY!

I am not sure whether it is necessarily a complete waste of time. I suppose it might depend on the type of individual you are targetting. If, for example, you are recruiting a social media executive, Facebook would surely be one of the first places to start?!